Control system



N. L. PELLERIN ET AL 2,874,714

Feb. 24, 1959 CONTROL SYSTEM 5 Sheets-Sheet 1 Fild March 4. 1953 INVENTORS 1 fiarmdnfifaikzz'nl fizwzlsli'levy 8 BY M... 224% ATTORNEYS Feb. 24,1959

Filed Marph 4, 1953 N. L. PELLERINI ET AL CONTROL SYSTEM 3 Sheets-Sheet 2 N I INVENTORS jVpz-yv'lzlfiileiz'iz E'MZISXZeV g,

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ATTORNEYS Feb, 2 1959 "N. L. PELLERIN ETAL 2,874,714 k I CONTROL SYSTEM 5 Sheets-Sheet s Filed March 4, 1953 IN VENTORS jVarz-z'al.f ellerz7a X lei/ y BY ATTORNEY;

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2,874,714 CONTROL SYSTEM Norvin L. Pellerin, Metairie, and FrancisX. Levy, New Orleans, La.; said Levy assignor to said Pellerin Application March 4, 1953, Serial No; 340,324 Claims. (Cl. 131-93 This invention relates to a control system, more specifically to a system for controlling the injectionof'supplies in a washing machine. l

Commercial laundries employ washing machines which require various supplies. For example, most machines require one type of soap (or soap and alkali combina-. tion) for the break, a lukewarm water operation to dissolve albumen stains and other stains which might be set by hot water. A second type of soap is requiredfor'a second sudsing operation, and sometimes third and fourth types of soap are required for successive sudsingoperations. In addition, bleach is required for a bleaching operation (sometimes performed in conjunction with one of the sudsing operations) and then, after a number of clear rinses, a solution on the acid side is required for a sour operation to neutralize any remaining 1 alkali. Finally, there may be a bluing operation, the purpose of which is well known, which requires a suitable bluing Several different typesof systems have beenemployed in the prior art to provide supplies forwashing machines.- Qne of these schemes involves filling small containers with estimated amounts of supplies-for given operations and then injecting the supplies from thecontainrs into th'e machine at the proper times. It is obviousthat this method of injecting supplies requires thatan operator fill the containers for'each cycle of the machine and is dependent upon the operators own'estimateof the amount ofjsupplies which will be required for the particular load going into the machine. The. operation of such systems is subject to various inaccuraciesibecause of poor judgmentonthe part of the operator and the-fact that-different loads of clothes require different amounts of the various supplies. i it a More recent supply systems employ electric controls responsive to the amount of suds'produced upon injection of a supply, but such systems suffer from the fact that ice / novel supply injection system which isresponsive to the control system including a thyratron tube and cooperating 1 concentration of supply in solution.

A further object of the invention is to provide a supply injection system which will inject washing agents in proper amounts and according to a predetermined sequence.

Another object of the invention is to provide a novel relay circuits.

Still another object of the invention isto provide a system" for automatically injecting a plurality of different supplies according to a predetermined sequence.

Yet another object of the invention is to provide a system for injecting supplies into a solution at given times and for arresting the flow of the supplies in response to the concentration of the solution. 1

r A further object of the invention is to provide a control system for injection of'plural supplies, which system in-' cludes individually adjustable control elements responsive to the injection of individual supplies. 1 An additional object of: the invention is to provide a I washing machine system including a supply dispenser, hot and cold water valves, and a dump valve, all interconnected in a manner which ensures eflicient and economical operation. i q i Another object of the invention is to'provide a washing machine control system having novel circuits for admit- 1 ting and expelling"the'necessary washing ingredients.

These and other objects of. the" invention are accomplished in a manner set forth in the following specification taken in conjunction with the accompanying drawings, in which: i

Figure 1 illustrates schematically a preferred embodiment; r

Figure 2 illustrates a portion of the circuit in more detail; and

Figure 3 illustrates 'a' modified circuit. V

Briefly, the invention comprises a plurality of supply injectors "which may be'actuated according to a predetermined sequence. Upon actuation of a specific injector, a corresponding thyratron controlcircuit is made opera tive and responsive to the conductivity of a solution as which thesupply is fed. When-the=solution reaches a predeterminedconcentration, the control circuit arrests the flow of supply. According to' the invention, novel water valve circuits and dump valve circuits are interconnected with the supply circuits in a manner which ensures accurate control and avoids the improper and many currently employed detergents'produce no substan- I tial suds, and thus the amount'of suds produced is not an accurate measure of the detergent required for a-given load of clothes. Furthermore, such systems are unresponsive in bleaching and bluingoperations. t

. Certain prior art .devicesutih'ze the conductivity of a provide a system for injecting supplies into a washing machine in a manner that avoids theundesirable characteristics of prior art devices.

A- further object of the invention is to provide a supply injection system which is completely automatic. I An additional object ofthe invention isv to provide a uneconomical operation of prior art systems.

Referring to Fig. l of the drawing, a washing machine 10 is schematically illustrated by a tub containing a washing solution. For automatic operation, a timer motor 11 is energized, upon closure of 'switch13, from the 24 volt secondary 12a of a power transformer 12, the primary of which is connected toa standard 115 volt A. C. line. The timer motor may be a conventional synchro nous motor arranged to drive a series of cams which in turn operate switches referred to below. The construction of timer motor and earns is conventional, and the connections between the motor andswitches have merely been indicated by clash lines. .It'will be understood that the timer motor may control notonly the switches shown,

but also the usual washingmachine elements. The

switches, when not otherwise described, may befimerely the single pole, single throw type well known in the art.

See Fig. 2 for .amore detailed showing of th ti switch arrangement.

' Hot'and cold water is supplied to the machine throughpipes 14 and 15 upon energization of water solenoid" valves 16,17 by operation of water switch 18. The water control circuit will be more fully described hereinafter. Appropriate supplies designated A and B are injected K into the machine through pipes 19 and 20, upon Ienergiza- Patented Feb. 24, 1959 3 tion of supply injectors 21 and 22 by closure of switches 23 and 24, respectively. The.construction of the injectors is not critical, and they may; for example, be constituted by solenoid-actuated valves arranged to regulate the flow of supplies from suitable reservoirs. In order to simplify the description only two-supply circuits have been illustrated, butit is evident that any number of supply circuits maybeprovided. A solenoid-actuated dump valve 25 is provided to empty the tub at the proper time upon deenergizationof dump valve solenoid 26 by opening of dump switch 27.

- 'In order to detect the concentration of the solution in themachine an electrode 28 is immersed in the solution at a point .well below the lowest water level which would be obtained in normal operation. The electrode is constructed of a non-corrosive metal and is insulated from the tub; A potential is supplied between this electrode and the remainder of the machine, which is grounded as shown. The variation in conductivity of the solution between the electrode 28 and the tub is employed to trigger a thyratron 9. Thyratron 29 is a conventional gas filled tube and may include a cathode 30, a control grid 31, a screen grid 32, a plate 33 and a heater filament 34. The cathode and screen grid may be grounded as shown. Filament potential is obtained from a 6.3 volt tap on the secondary of a transformer 35, the primary of which is energized from the 115 volt secondary 12b of transformer 12. Plate potential is supplied to the thyratron through the field coil of a relay 36 and the contacts of a relay 37.

Relay 37, a conventional timedelay switch, is energized from the secondary 12b and is arranged to close a few seconds after the application of operating potentials to the power transformer 12, the delay in closure being pro vided to allow filament 34 to heat cathode 30 to its normal operating temperature before application of a load to the thyratron. Of course the relay may be energized from secondary 1211, if desired.

Control grid bias for thyratron 29 is provided from a 12.6 volt terminal of the secondary of transformer 35, and the secondary is so connected that the control grid is energized in phase opposition to the plate 33. It will be noted that the control grid 31 is substantially isolated from the secondary of transformer 35 until closure of relay 38 or relay 39;

Each of relays 38 and 39, has two pairs of contacts. The closure of the left-hand pair of contacts on either relay places resistance 40 or resistance 41, as the case may be, across the secondary .of transformer 35. Simultaneously, the closing of either right-hand pair of contacts connects the control grid 31 to variable tap 42 or variable tap 43 on resistances 40, 41, respectively, which thus constitutes variable potentiometers. Relays 38, 39 are energized upon closure of switches 23, 24, respectively.

A variable calibrating resistor 44 is inserted in the circuit between the secondary of transformer 35 and the potentiometers 40, 41. A bleeder resistance 45 may be provided between the plate 33 and cathode 30 of thyratron 29. 7

It will be noted that the normally closed contacts of relay 36 are in the supply circuit including the 24 volt secondary 12a of transformer 12, as described above. The field coil of relay 36 may be shunted by a condenser to delay closing of its contacts once they have opened. Also in the supply circuit are the normally closed contacts of a relay 46, the center-tapped field coil of which is energized from water switch 18. Thus, if either half of the field coil of relay 46 is energized, corresponding to the energization of either of water solenoid valves 16, 17 by switch 18, the relay will open and prevent energization of the supply circuits. Since the fields produced by the halves of the field coil are arranged to be additive, the relay also opens if both halves are energized. This arrangement prevents the admission of supplies until the desired amount of water has been admitted.

Upon the application of operating potentials to transformer 12 and the closure of switch 13, the timer motor 11 begins its cycle. It will be clear that the timer motor and associated cams may be designed to close the switches 18, 23, 24 and 27 according to any predetermined sequence, and for the purposes of illustration, it is assumed that the timer motor first closes dump switch 27, thereby energizing dump valve solenoid 26 and closing dump valve 25. Next, the timer motor closes the water switch 18, which energizes water solenoid valves 16, 17, thereby admitting hot and cold water to the machine through pipes 14, 15. The amount of water admitted may be predetermined by the setting of the timer motor so that the water switch is opened after a given interval, or water level controls, to be described hereinafter, may be provided to close the water valves.

When the timer motor closes switch 23, the circuit through injector 21 from the 24 volt secondary 12a of transformer 12 is completed, assuming that dump switch 27, relay 36, and relay 46 are closed. Supply A will then' be injected into the machine through pipe 19. It will be noted that insertion of dump switch 27 in the energization circuits of injetcors 21 and 22 prevents injection of supplies into the machine when the dump valve 25 is open and avoids ,waste of supplies. The dump valve remains closed as long as dump valve solenoid 26 is energized through closure of dump switch 27.

Closure of switch 23 also completes the field circuit of relay 38, thereby closing the circuits through the two pairs of contacts controlled by this relay. The closure of these contacts places a potential on the control grid 31 of thyratron 29 determined by the position of the variable tap 42 of the potentiometer 40. The position of tap 42 has been predetermined to prevent the initial firing of the thyratron. As supply A is injected into the machine, the conductivity of the washing solution increases because of ionization of the supply, and consequently the current flowing between electrode 28 and the machine 10 through resistor 44 from the secondary of transformer 35 increases. This results in a less negative potential on the grid 31 at a time when the plate 33 is driven positive. Consequently, at some concentration of the washing solution determined by the position of tap 42 thyratron 29 fires. The sudden surge of plate current through the thyratron energizes relay 36 and opens its normally closed contacts, thereby breaking the circuit to injector 21 and arresting the flow of supply A to the machine. The contacts of relay .36 remain open as long as the thyratron fires on successive half cycles of plate potential. After a time determined by the maximum supply requirements, switch 23 is opened by the timer motor; relay 38 is deenergized, thus opening its contacts.

At a time determined by motor 11, switch 24 is closed, thereby energizing injector 22 and injecting supply B into the machine through pipe 20. Simultaneously relay 39 closes, and the cycle continues exactly as indicted with respect to supply A, that is, the conductivity of the solution increases until the thyratron 29 fires again, thereby reopening relay '36 and arresting the flow of supply'B. Since each 0 fthe supplies may cause a different change in the conductivity of the solution, the variable taps 42 and 43 may be individually adjusted to fire the thyratron when the washing solution reaches any desired concentration. These taps may be adjusted when the machine is first installed, and assuming that there is no change in formula or type of soap, bleach or other supplies employed, it will not be necessary to readjust these controls. It will ;be noted that as taps 42 and 43 are moved .downward, the control grid 31 when conn thereto more nearly approaches ground potential, and the tube thereby requires a proportionally smaller solution conductivity to commence firing.

The supply injectors 21 and 22 may control the admission of supplies from a central supply system as, for example, a tank ,of hot liquid soap, the soap being brought to the supply injector valves under pressure from a pump,

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but the invention is not limited to such a supply system and maybe operated with powdered supplies provided from a suitable conveyoror provided in a hopper. It should also be noted that each of the switches may be manually actuated rather than automatically. To provide for such operation it is only necessary to open switch 13, thereby disabling timer motor 11. Each of the switches may then be actuated by manual actuators.

Referring nowto Fig. 2, the water control circuit is shown in greater detail. The-switch 18- of Fig. 1 may actually comprise three switch elements 18a, 18b, and 18c, which are operated by associated cam's 47, 48, 49, respectively. It will be understood that each cam may have a particular contour and may be coupled to the timer motor by a particular gear train, so that the associated switch will close for a predetermined interval at a predetermined time and then will open. The switch blades may be spring biased against the cams. It should be noted that the switch and cam arrangement illustrated is intended to be representative of the type of arrangement which may be employed in connection with each of the timer driven switches of Fig. l.

Switches 18a and 18b are single pole, single throw switches, while switch 180 is a single pole, dou-ble throw switch which normally rests on one contact or the other. In addition to these switches, a. pair of float-controlled switches 50, 51 are employed; The latter are actuated through any well known mechanical means by float 52. The float may be restricted to vertical movement by a tubular chamber 53, which receives washing solution from the tub through port 54. It will be clear that the chamber 53 may form an integral portion of the tub. "Ihe float is provided with a rod 55, which supports a pair of vertically adjustable collars 56, 57. These collars may be'set at specific positions on rod 55 to provide high and low water level controls as will appear below. A suitable lever arrangement, indicated by dash lines, actuates switches 50, 51 from respective collars. As the float and lever arrangement per se are well known in the art, no further description is believed necessary.

It will be noted that an additional pair of relays 58, 59 is arranged to control the continuity of the timer motor circuit. The field coils of these relays are energized from the water control circuit. This arrangement deenergizes the timer motor while water is admitted to the machine and ensures that desired water levels are reached before proceeding with the washing cycle. Of course a centertapped relay such as relay 46 could be employed in place of relays 58, 59..

It will be further noted that relay 46 has been provided I with a second pair of contacts and is arranged to control the continuity of the plate supply circuit for thyratron29. Thus the plate circuit is broken while water isinjected into the machine. This modification ensures that thyratron 29 deionizes, and prevents the continued firing of the thyratron which might voccur if electrode 28 were immersed in a concentrated washing solution remaining after the machine is dumped and prior to refilling with fresh water. 7

The water control circuit can be traced from transformer 12 through either of switches 18a, 18b, through eitherof solenoid ,valves 16, 17, through switch 18c, through either of switches .50, 51, back to the transformer. Switch 18a controls the admission of hot water; switch 18b controls the admission of cold water; and switch 180 constitutes a high-low levelswitch.

For certain operations it is desirable to have a high water level and for other operations a low level. Switch 180 thus completes the circuit to either switch 50 or switch 51 depending upon whether a high or low level is desired; Switches 50, 51 remain closed until opened by collars 56, 57, respectively, when the predetermined water levels are obtained. a

In operation, timer motor 11 closes either or both of switches 18a, 18b, and also moves switch 18c to a .6 predetermined position. ither or both of valves 16, 17 are; eneregized and relays 46, 58, 59 open. When a predetermined water level is reached, switch 51 opens, and if switch 18c is in its lower position, the water circuit is interrupted. Assuming that switch 18c is in .its' upper position, the'water level rises until switch 50 opens, whereupon the water circuit is interrupted. In either case, relays 46, 58, 59 reclose.

Fig. 3 illustrates a modifiedlcircuit for controlling the grid potential of thyratron 29. Each of relays 38, 39, energized as described previously, now. has only a single pair of contacts. As can be clearly seen from the drawing, closure of these contacts connects variable taps 60, 61 to electrode 28. These taps cooperate with resistors 62, 63, respectively, which thus constitute variable potentiometers. An additional potentiometer 64, having a variable tap 65, shunts the current path between electrode 28 and ground. Tap provides an adjustable grid bias to control grid 31 of the thyratron. Potentiometers 62, 63 are adjustable for individual supplies and may have moderate values, for example, 500 ohms total resistance. The arrangement of Fig. 3 provides sensitive, yet economical control.

In operation, relays 38, 39 close individually as before, upon closure of switches 23, 24, respectively. Thyratron 29 remains quiescent until the conductivity of the solution between' electrode 28 and'ground increases to the point where the potential at tap 65 is insuflicient to prevent firing of the tube when the plate is driven positive. This conductivity is' predetermined by the positions of taps 60, 61 and also by the position of tap 65.

It will be noted that in the embodiment of Fig. 3, where grid 31 is normally isolated from ground by resistor 64, and also in the embodiment of Fig. 1, where the grid is normally floating, the thyratron may fire when operating potentials are applied to the circuit, since the grid potential may be above the critical level. This condition does not detract from the proper operation of the invention, however, for as soon as either of relays 38, 39 is energized, a suflicient bias is applied to the control grid to prevent firing of the tube once the tube is deionized (during thenegative halffcycle of plate potential). Relay 36 will then remain closed until the grid potential rises above the critical level. If desired, this extraneous firing may be prevented by providing an additional relay (similar to relays 38, 39) and .an additional bias resistor (connected as 40, 41 or 62, 63) The relay maybe arranged to connect the additional resistor to grid 31 when neither ofswitches 23, 24 is closed and to break this connection when either switch is closed. An even simpler expedient in Fig. 3 would be to provide each of relays 38, 39 with an additional pair of contacts connected in series-with a bias resistor and the control grid. Both pairs of contacts would be arranged to be closed only when relays 38, 39 are deenergized. a

It will be clear to those skilled in the art that this in-v vention provides an effective system for controlling the dispensing of supplies; The system is not limited to washing machines, nor to specific supplies or supply dispeners. Although a preferred embodiment has been shown and described, the invention is not limited to the details of this embodiment. It will be evident to those skilled in the art that various modification may be made without departing from the spirit and principal concepts of the. invention. For example, a master power supply provided with a voltage stabilizer and isolation transformer may be employed to energize control circuits for a plurality of machines. Separate filament and plate supply transformers may be employed. Signal devices may be provided to indicate the beginning'or comple-, tion of operations. Moreover, the system is not restricted to new equipment but may be added to existing installations.

We claim:

1. In combination, a plurality of supply injectors, means for energizing said injectors according to a predetermined sequence, solution containing means for receiving supplies from said injectors, and means for deenergizing said injectors in response to the concentration of corresponding supplies in solution.

2. In a washing machine system, a tub, means for injecting water into said tub, a plurality of means for injecting supplies into said tub, dump valve means for draining said tub, timer means for energizing said water injecting means, said supply injecting means, and said dump valve means according to a predetermined cycle, means for sensing the conductivity of washing solution in said tub, and means for deenergizing each of said supply injecting means in response to predetermined conductivities of said washing solution.

3. In combination, a supply receiver, a pair of supply injector means for injecting supplies into said receiver, means for individually energizing said supply injector means, means for deenergizing said supply injector means, means for detecting the concentration of supplies in said receiver, a pair of coupling means operable to couple said detecting means to said deenergizing means, and means for operating one of said coupling means in response to energization of a corresponding injector means.

4. ln combination, a pair of supply injectors, a corresponding pair of relays, means for energizing individual injectors and corresponding relays according to a predetermined sequence, means for deenergizing said supply injectors, sensing means responsive to the concentration of supplies injected, and means actuated by said relays for coupling said deenergizing means to said sensing means.

5. In combination, a vessel, an electrode mounted interiorly of said vessel and electrically insulated therefrom, means for applying a potential between said electrode and said vessel, a plurality of means responsive to the potential applied between said electrode and said vessel, a corresponding plurality of means for injecting supplies into said vessel, means for immersing said electrode in an aqueous supply-containing solution, means for energizing said injecting means, and means for deenergizing said injecting means in accordance with signals from a respective potential responsive means.

6. In combination, a tub, means for providing an aqueous vehicle in said tub, a plurality of means for injecting supplies into said tub, an electrode immersed in said vehicle and insulated from said tub, means for applying a potential between said electrode and said tub,

a plurality of potentiometers each having an impedance and a cooperating tap, a grid actuated discharge device having associated energization circuits, means for individually energizing said injecting means, means for individually connecting said impedances between said electrode and said tub, means for individually connecting said taps to said grid, and means responsive to a change in operating condition of said discharge device for deenergizing said injectors.

7. In combination, a vessel adapted to receive water and a plurality of supplies to form a solution, a first supply injector coupled to said vessel, first switch means for energizing said first supply injector, a second supply injector coupled to said vessel, second switch means for energizing said second supply injector, a water injector coupled to said vessel, third switch means for energizing said water injector, drain valve means for draining said vessel, fourth switch means for energizing said drain valve means, means for actuating said four switch means according to a predetermined schedule, and means responsive to the conductivity of the solution in said vessel for deenergizing said supply injectors.

8. The invention of claim 2, further including means for deenergizing said Water injecting means in response to water in said tub at a predetermined level.-

9. The invention of claim 2, further including means for rendering said timer means. inoperative in response to energization of said Water, injecting means.

10. The combination of claim 6, further including means for interrupting the anode energization circuit of said discharge device upon operation of said vehicle providing means.

11. In combination, a supply receiver, a supply injector eoupled'to said receiver, means for energizing said supply injector, means for measuring the concentration of supply in said receiver, means responsive to said measuring means for deenergizing said injector, and means for energizing said measuring means upon energization of said injector means.

12. The combination of claim 11, wherein said means for energizing said measuring means comprises a source of potential and an impedance connected in series with said measuring means, and wherein said means for de energizing said injector comprises a grid controlled discharge device having its grid coupled to said measuring means.

13. In a device of the type described, an electron tube including a cathode, a control grid, and an anode, a load connected to said anode and cathode, a plurality of grid bias devices, means for individually coupling said bias devices to said grid according to a predetermined sequence, a vessel for holding liquid, means therein for sensing the conductivity of the liquid, means for coupling said conductivity sensing means to vary the potential of the sequentially determined one of said bias dcvices to change the load, a plurality of means operable to add miscible elements to said liquid, means for rendering said element-adding means operative simultaneously with the coupling of a respective bias device with said grid, and means for rendering said element-adding means inoperative in response to a change in current through said lead.

14. In a system of the type described, a receptacle, means for adding liquid to said receptacle, means for adding a supply to said receptacle, means for dumping the contents of said receptacle, means for operating said liquid adding, supply adding, and dumping means, respectively, and means for preventing operation of said supply adding means in response to operation of said liquid adding means or said dumping means.

15. In the system of claim 14, means for detecting the concentration of said supply in said liquid, and means responsive to said detecting means for preventing operation of said supply adding means.

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